12 
down by the workmen's feet. It appears, therefore, 
that the seeds of these fuci, floating about abundantly 
in the waters of the Frith of Forth, must have attach- 
ed themselves to the dressed surface of the sandstone 
after the middle of November, and must have vegeta- 
ted and increased with great rapidity during a winter 
yemarkable for severity: for this, it will be remember- 
ed, was the winter of the great frost as it was styled, 
which continued nearly the whole of the month of Ja- 
nuary 1814, and of which a very full account will be 
found in the Scots Magazine for February of that year. 
Other circumstances, it may be observed, were here 
favourable to their growth. During the winter and 
spring months, the Carr Rock must have been almost 
constantly under water. The incessant struggle of the 
tides at Fifeness is calculated to produce that degree of 
agitation which has long been considered favourable to 
the growth of the stronger sea-weeds ; and this does 
not seem to have been interrupted by the rolling of 
heavy waves for many weeks during winter. 
If, however, still further proof of the rapid growth 
were wanted, the experience of the following season 
afforded ample evidence. In autumn 1814, a course 
of large hewn freestone was completed, and the ope- 
rations were again suspended till the following sum- 
mer, It was as late as the beginning of July 1815 be- 
fore the weather permitted boats to approach the reck 
at low water; when, on the new course of the beacon, 
a crop of Fucus esculentus was found, the fronds of 
which measured on an average six feet long, and were, 
as before, furnished with pinne. This must of neces- 
sity have been the grotvth of not more tham eight 
months from the time of the very minute seeds haying 
attached themselves to the hewn stone. 
The opinion of Lamouroux, therefore, that during 
winter the vegetation of sea plants is suspended like 
that of land plants, is proved to be erroneous. 
It may here be mentioned, that Dr Walker states, * 
on the authority of the kelp-makers, that “ sea-weeds 
do not grow so much in seven years upon freestone as 
they do in two years on whinstone.” The facts above 
detailed shew that this remark is not universally appli- 
cable, although it may be true of the loose masses of 
stone on the shores, which, if soft, must be liable to 
be worn by the striking of smaller boulder stones. 
It is not improbable, that the growth of the large pe- 
lagic fuci may even be much more rapid than that now 
described. The Fucus giganteus of the Pacific Ocean 
attains several hundred feet in length: Forster mentions 
specimens even 800 feet long. In the bays of this coun- 
try, F. filum frequently reaches 30 or 40 feet, and in 
some places, as Sealpa Flow in Orkney, this is consi- 
dered as the growth of the summer and autumn months, 
from May to October. 
General Structure, &¢c. of Fuci. 
From the characters of the orders in Lamouroux’s ar- 
rangement, some notion of the general structure of the 
different tribes of marine plants must already have been 
acquired. In treating farther of the same subject, bre- 
vity shall therefore be studied. 
In general it may be observed, that some species are 
coriaceous, often branched and shrub-like ; some are 
membranaceous, and traversed by a longitudinal nerve 
or midrib ; others are filiform, generally not jointed : 
they produce receptacles, tubercles, or capsules; and 
most of them aré furnished with air-vesicles. 
Decandolle considers marine plants as composed.en- 
FUCI 
tirely of cellular tissue; attributing the 
ture observable in the stems, the mid-ribs or nerves, and 
the frends, to modifications in the form of this cellular 
tissue. Mirbel is of the same epinion. It is certain 
that all the parts of sea plants are much more near- 
ly of uniform texture than in land plants in general ; 
most of them seeming to be capable of into 
others ; the peduncle becoming a branch, the air-ve- 
sicle a frond, and so on. Lamouroux, however, has 
remarked, that the stem of Fucus digitatus is form- 
ed of four distinct parts, analogous in situation, relative 
size, and even organization, to the epidermis, bark, 
-wood and pith of dicotyledonous plants. met mee 
ires some aid from the imagi to enable 
observer to see all this. But it is certain that a section 
of the stem of Fucus digitatus forms a curious micro- 
scopic a and that it is distinctly perceived to be 
composed of longitudinal parallel jointed’ colourless 
fibres, disposed in concentric circles, and 
a pretty solid mass. Lamouroux has like- 
wise discovered, or imagined he has discovered, in cer- 
tain sea-weeds nelonaoy to different tribes, most of 
the characters which distinguish the brilliant corollas of 
phenogamous plants, the stems and leaves of trees, 
and the herbaceous structure in general. — oar. 
That marine alga are not furnished with continuous 
vessels of the same nature as those of land 3, is ob- 
vious, from the well known remark, that if one portior 
of a sea plant be plunged in water, and the other : 
posed to the air, only the immersed portion remains in 
vigour; no fluid seems to rise ily enough throug 
the frond to nourish or refresh the other part of th at. . 
The result of microscopic observation, and att fat 
injection, rt the same view. On the other , 
the fructification of some families, as the Fuecacee and 
Floridee of Lamouroux, is observed to be placed almost 
always on the stems or branches, near to 'the masses of 
fibres, or at their extremities. In the Dictyodes ofthe 
same writer, the more regular and visible the structure 
of the reticulations, or cellular tissue, appears, the si- 
tuation of the fructification is found to be more uni- 
‘form; and the less regular and distinct, the ‘fiructifiea- 
‘tion is more scattered. The 
production of capsules re- 
gularly at the extremities of branches or fronds, which 
is observed in many species, proves the existence of 
some kind of vessels, and the elaboration of partiedlar 
fluids. Upon the whole, therefore, as ingana- 
logous to circulation is indispensable, the masses of fi- . 
bres, or cellular tissue with lengthened cells, may be 
considered as calculated to perform the functions of 
longitudinal vessels. Horizontal vessels are distin 
seen in some species, particularly F. vesiculosus an 
nodosus. : 
Some of the fuci are quite cartilaginous in texture ; 
such as the stem and midrib of F. eseulentus, and the 
whole plant of F. aculeatus. A few species dissolve 
‘into jelly on being placed in boiling hot water. Some 
are quite flexible when recent, and become stiff and apt 
to break when dry: others, on thé contrary, as th 
nus Dictyopteris of Lamouroux, are stiff and fran 
when living, and become flexible when dried. 
The jointed structure of the. frond was 
dered as characteristic of Conferve; but this, it “is 
now admitted, does not effectually distinguish them 
froma several fuci, such as F. fruticulosus and pinastroi- 
des, or even some lichens and fungi ; and it has there- 
fore been abandoned as a generic disti .  Lamou- 
roux remarks, that itis easy to distinguishtthe truly ar- 
® ‘Transactions of the Highland Soviety, vol. i, p. 2% 
difference of struc:  Fuci. 
long consi- Jointed | 
